- An Expeditious Synthesis of 1-(4-Chlorophenyl)-3,3-dimethyl-2-butanone by a Ligand-Free Palladium-Catalyzed α-Arylation of Pinacolone: Scale-Up and Effect of Base Concentration
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An efficient and large-scale synthesis of 1-(4-chlorophenyl)-3,3-dimethyl- 2-butanone (1) by an α-arylation of pinacolone (2) with 1-bromo-4-chlorobenzene (3) in the presence of palladium acetate and sodium f-butoxide in toluene is described. An increase in the concentration of sodium t-butoxide to 2.5-3.0 equivalents suppressed the formation of over-arylated products. These ligand-free conditions afforded a yield of 1 that was comparable to those obtained by using a ligand.
- Prashad, Mahavir,Liu, Yugang,Repic, Oljan
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- Identification and biological characterization of 6-aryl-7- isopropylquinazolinones as novel TRPV1 antagonists that are effective in models of chronic pain
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Vanilloid receptor 1 (VR1, TRPV1) is a cation-selective ion channel that is expressed on primary afferent neurons and is upregulated following inflammation and nerve damage. Blockers of this channel may have utility in the treatment of chronic nociceptive
- Culshaw, Andrew J.,Bevan, Stuart,Christiansen, Martin,Copp, Prafula,Davis, Andrew,Davis, Clare,Dyson, Alex,Dziadulewicz, Edward K.,Edwards, Lee,Eggelte, Hendrikus,Fox, Alyson,Gentry, Clive,Groarke, Alex,Hallett, Allan,Hart, Terance W.,Hughes, Glyn A.,Knights, Sally,Kotsonis, Peter,Lee, Wai,Lyothier, Isabelle,McBryde, Andrew,McIntyre, Peter,Paloumbis, George,Panesar, Moh,Patel, Sadhana,Seiler, Max-Peter,Yaqoob, Mohammed,Zimmermann, Kaspar
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p. 471 - 474
(2007/10/03)
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- Catalysis by Ferrous Ion in Nucleophilic Aromatic Substitution Reactions
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Efficient catalysis is provided by ferrous chloride in the nucleophilic aromatic substitution reaction of several aryl and heteroaryl halides with a ketone enolate ion as the nucleophile in Me2SO, to give the aryl or heteroaryl ketones in fair to good yields.The enolate ions from pinacolone, acetophenone, cyclohexanone and pentan-3-one behave successfully.A side-reaction is represented in some cases by the hydrodehalogenation of the substrate ArX, and evidence is provided for the intermediacy of both Ar(radical) and Ar(anion) species.Other significant mechanistic clues acquired include: (i) inhibition by electron and radical scavengers; (ii) entrainment of poor nucleophiles by good ones; (iii) the relative reactivity of two nucleophiles in competition experiments with Phl under Fe2+ catalysis having the same value as in the experiments under both photostimulation and spontaneous initiation.All these findings are consistent with an SRN1 mechanism of substitution where ferrous ion, in combination with the nucleophile, plays an important role in the initiation step.
- Galli, Carlo,Gentili, Patrizia
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p. 1135 - 1140
(2007/10/02)
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